14.5.0: sanitize_utf8_filename() can call transliterator_transliterate() when ext-intl is unavailable

[lverane]

Reproduction:

PHP 8.2
intl extension disabled
WordPress 7.0.2
BuddyPress 14.5.0
Upload avatar with UTF-8 filename

Cause:

In sanitize_utf8_filename() both instances of function_exists( 'wp_is_valid_utf8' ) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval ) should be wrapped in parentheses.

File: /wp-content/plugins/buddypress/bp-core/classes/class-bp-attachment.php
Lines 297 - 322

[espellcaste]

@lverane I don't get it. What's exactly the problem? Is there an error you can share?

In sanitize_utf8_filename() both instances of function_exists( 'wp_is_valid_utf8' ) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval ) should be wrapped in parentheses.

What does that mean exactly?

[lverane]

Replying to espellcaste:

@lverane I don't get it. What's exactly the problem? Is there an error you can share?

In sanitize_utf8_filename() both instances of function_exists( 'wp_is_valid_utf8' ) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval ) should be wrapped in parentheses.

What does that mean exactly?

I added the file path to the ticket description. The issue is that the current if statement

if (
  function_exists( 'transliterator_transliterate' )
  // wp_is_valid_utf8 is added in WP 6.9.
  && function_exists( 'wp_is_valid_utf8' ) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval )
) {

Will resolve as

(function_exists( 'transliterator_transliterate' ) && function_exists( 'wp_is_valid_utf8' )) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval )

Meaning if function_exists( 'transliterator_transliterate' ) is false and seems_utf8( $retval ) is true transliterator_transliterate() is still called. The fix is to add parentheses around the second evaluation:

function_exists( 'transliterator_transliterate' ) && (function_exists( 'wp_is_valid_utf8' ) ? wp_is_valid_utf8( $retval ) : seems_utf8( $retval ))

Same issue/solution for function_exists( 'iconv' ) on the else statement.